Method and apparatus for making toothed lock washers



F SCHMIDT ET AL May 7, 1968 METHOD AND APPARATUS FOR MAKING TOOTHED LOCKWASHERS Filed Oct. 20, 1965 3 Sheets-Sheet 1 a i ig INVENTORS FREDScHMIIDT MlcHm-zl. s s-nqRl-r BY y W QTTOEN vs y 1968 F. SCHMIDT ET AL3,381,514

METHOD AND APPARATUS FOR MAKING TOOTHED LOCK WASHERS Filed Oct. 20, 19655 Sheets-Sheet Z I w [.1 w

INVENTOES FRED SCHMIDT M ICHFIEL 5. STA arm 5v QTTO NEVS U OZUM FWISLIF. SCHMIDT ET AL '6 Sheets-Shae INVENTORS FEED ScHMnDT MICHHEL. S. S'mmmv HTTOR vs May 7, 1968 METHOD AND APPARATUS FOR MAKING TOOTHED LOCKWASHERS Filed Oct. .20, 1965 United States Patent 3,381,514 METHOD ANDAPPARATUS FUR MAKENG TGOTHED LUCK WASHERS Fred Schmidt, Cranford, andMichael S. Stnrita, Scotch Piains, N.J., assignors to Triangle ToolCompany,

Union, N.J., a corporation of New Jersey Filed Oct. 20, 1965, Ser. No.4%,497 14 (Iiaims. (Cl. 72-335) ABSTRACT GE THE ENCLOSURE A method andapparatus for making toothed lock washers from sheet material whereinthe body of the lock washer is blanked from the sheet material but isnot removed therefrom and is held by frictional engagement in the sheetmaterial so that the teeth of the lock washer body and the sheetmaterial lying between the teeth are twisted while the body is retainedin the sheet to establish locking edges on the teeth displaced axiallyfrom the surface of the remaining portion of the body.

The present invention relates generally to methods and apparatus formanufacturing toothed lock washers. More specifically, the inventionpertains to methods and apparatus for fabricated toothed lock washersrapidly and accurately from a continuous elongated strip of sheetmaterial.

Toothed lock washers of the variety which include a generally annularbody portion with looking teeth projecting radially from the bodyportion and being twisted relative thereto have enjoyed wide commercialacceptance. While the configuration of such lock washers would appear tobe relatively simple, such simplicity is deceptive when considered inlight of the rapid and efficient fabrication which is necessary toreduce the cost of manufacture to a competitive minimum whilemaintaining the quality necessary for proper operation of such lockwashers. It has been found that the locking properties of toothed lockwashers are directly related to the amount and consistency of the twistin the teeth and to the establishment of adequate locking edges alongthe twisted teeth. Thus, it would be advantageous to have availablemethods and apparatus which are capable of attaining rapid manufacturewith accurate control over the essential characteristics of such lockwashers.

It is an object of the invention to provide a method and apparatus bywhich toothed lock washers may be fabricated rapidly and efficientlywith increased uniformity and quality.

Another object of the invention is to provide a method and apparatuswhereby toothed lock washers may be economically and accuratelyfabricated from an elongated strip of sheet material stock with theminimum waste of stock.

Still another object of the invention is to provide a method andapparatus by which the teeth of a toothed lock washer may be accuratelyformed and uniformly twisted to present the requisite locking edgesalong the teeth.

The invention may be described briefly as a method of making toothedlock Washers from sheet material, each washer having a generally annularbody portion with teeth projecting radially therefrom and being twistedrelative thereto to establish locking edges displaced axially from atleast one surface of the body portion, the method comprising the stepsof forming a blank having a body with radially projecting portionscorresponding .to the teeth of the finished lock washer by severing theblank from the sheet of material around the entire outer periphery ofthe blank, retaining the formed blank within the sheet by frictionalengagement of at least a portion of the severed periphery of the blankwith the sheet material, subsequently twisting the radially projectingportions while the blank is retained in the sheet by the frictionalengagement to establish the requisite locking edges, and removing thebody with the twisted teeth from the sheet. The invention furthercontemplates apparatus for making toothed lock washers as describedabove, the apparatus comprising means for performing each of the stepsset forth above. The means are located in such a manner as to fostereconomical utilization of manufacturing apparatus and conservation ofsheet material. stock.

The invention will be more fully understood and further objects andadvantages thereof will be made apparent in the following detaileddescription of an embodiment of the invention illustrated in thedrawing, in which:

FIGURE 1 is a plan view of a typical toothed lock washer;

FIGURE 2 is an elevational view of the toothed lock washer of FIGURE 1;

FIGURE 3 is a plan view of an elongated strip of sheet materialillustrating steps in the fabrication of the toothed lock washer ofFIGURE 1;

FIGURE 4 is a plan view of apparatus for fabricating the lock washer;

FIGURE 5 is a cross-sectional view taken along line 5-5 of FIGURE 4;

FIGURE 6 is a cross-sectional view taken along line 66 of FIGURE 4; and

FIGURES 7 through 11 are enlarged diagrammatic views illustrating theindividual steps performed by the apparatus of FIGURES 4 through 6.

Referring now to the drawing, FIGURES 1 and 2 illustrate a typicaltoothed lock washer it which is shown having a generally circularconfiguration including a generally annular body portion 12 with aplurality of external locking teeth ltd projecting radially outwardlytherefrom. A central aperture 16 communicates with the opposite surfacesof body portion 12 for cooperating with a threaded fastener element in awell known manner. Teeth ltd are twisted relative to the body portion 12so as to present upper and lower locking edges 18 along the teeth, whichlocking edges are axially displaced from the opposite surfaces of thebody portion 12.

It has been found that the effective operation of a toothed lock washersuch as washer lid is dependent upon the presentation of well definedlocking edges along the teeth. A sharp edge will increase the bitingcapabilities of the teeth while a uniform, controlled amount of twist inthe teeth will assure that every tooth is equally effective inpresenting locking edges to mating fastener elements and in establishingthe desired torsional reaction forces which give rise to the lockingforces attained from the utilization of such toothed lock washersbetween mating fastener elements. Therefore, the invention is directedtoward method and apparatus for attaining these desirablecharacteristics.

Turning now to the remaining figures, FIGURE 3 shows a longitudinallyextending elongated strip Zti of sheet material with a series of toothedlock washers in various stages of fabrication in a method ofmanufacturing a number of lock washers lilfrom sheet material. Themethod is best described in connection with the apparatus illustrated inFIGURES 4 througn 6 and the diagrammatic illustrations of FIGURES 7through 11.

The strip 20 is advanced in predetermined increments through a die set39 having an upper platten 32 and a lower platen 34. Upper and lowerplattens 32 and 34 are arranged for relative reciprocating motion bymeans of the cooperation of rods 36, fixed to upper platten 32, withsockets 33, fixed to lower pl'atten 34. An upper tool carrier $0 isfixed to the upper platten for movement therewith while a stripper plate41 is carried for resilient movement relative to the tool carrier 4%,the stripper plate 41 being aligned with the tool carrier by means oflocator pins 42 engaging complementary bushings 44. A lower tool carrier46 is likewise fixed to the lower platten. The upper platten 32 isviewed from below so as to illustrate the various operating toolscarried by the tool carrier 40 while the lower platten 34 is viewed fromabove so as to show the various stationary tools which are fixed in toolcarrier 46 and are complementary to the reciprocating tools carried bythe upper plattcn. The movable tools carried by the upper platten areduplicated to provide three separate series of tools, each series beingcapable of producing a lock washer 10 in strip 20 as the stripprogresses through the die set. The reasons for providing threeindependent series of tools will be discussed later. For the purpose ofthe present discussion one such series will be described in detail andit is understood that the remaining series operate in a similar manner.

The first series of operating tools carried by the upper plattencomprises a piercing punch d, a blanking punch 52, an anvil 54, aforming punch 56, a push rod 53, and a cut-off blade 59, each fixed inthe upper tool carrier it? for reciprocating movement with the upperplatten. Each of the tools 50, 52, 54, 56, 58 and 59 is located along alongitudinal line A corresponding with longitudinal line AA in strip 20.Lower platten 34, which is normally stationary, likewise carries threeindividual series of tools in the lower tool carrier 46, each of whichseries is complementary to a like series in the upper relatively movableplatten. Thus, the tools of the first series held in the lower toolcarrier 46 of the lower platten comprise a die 60 for cooperating withpiercing punch St}, a blanking die 62 including a concentric,resilicntly supported stop member 63 for cooperating with blanking punch52,'an anvil 64 complementary to anvil 54, a forming die 66complementary to forming punch 56 and a stationary cut-off blade 69 forcooperating with reciprocating blade 59. The lower too-l carrier andplatten also include a first chute '70 below piercing punch 55% and asecond chute 72 below push rod 58.

As best seen in FIGURE 5 viewed in connection with FIGURES 3 and 7through 11, lock washers are fabricated by the following procedure:Strip 20 is advanced from left to right, as viewed in each of thesefigures in predetermined increments so as to position any givenlongitudinal location along the strip, such as that indicated by lateraldashed line L in FIGURE 3, between one of the complementary sets oftools in a particular series. The strip is first pierced by piercingpunch 59 to establish an aperture 74 which will correspond to thecentral aperture 16 in the finished lock washer, the scrap 75 passingout of the apparatus through chute 70. The strip is then advanced sothat the pierced location is positioned between complementary blankingpunch 52 and blanking ie 62. The blanking punch 52 is provided with ribs80 and the blanking die has complementary grooves 82 so that uponreciprocation of the upper platten the strip is blanked to form a flatblank illustrated in the form of body 76 with radially projectingportions 78 corresponding to the teeth 14 in the finished lock washer,the ribs (it) and grooves 82 assuring that portions 73 have welldefined, sharp cornered edges corresponding to edges 18. It is notedthat this blanking operation does not actually displace the blanked body7 6 completely out of strip 20, but merely displaces the blanked bodyout of the plane of the strip, stop member 63 assuring that the blankedbody is still located within the sheet. The strip is then indexed toplace location L and the blanked body between anvils 54 and 64 andreciprocation of these corresponding tools will push the blanked body'75 back into the strip 20 wherein the blanked body is retained byfrictional engagement of the periphery of the body with the surroundingsheet material. It is noted that at this point blanked body 76 iscompletely severed along its entire periphery from the strip 2% but isretained in the strip solely by the frictional engagement between theperiphery of the blanked body and the surrounding sheet. The die set isagain opened and the strip is again advanced to position location Lbetween forming punch 56 and forming die 66. The forming punch 56 isprovided with angled faces 84 and the forming die 66 has complementaryangled faces 86 such that reciprocation of the upper plattcn will bringthe complementary punch 56 and die 66 into engagement with the blankedbody 76 and the angled faces 84 and 86 will twist the blanked bodyportions 78 through a desired angle to establish teeth 14 with lockingedges 13 displaced axially from the surfaces of body portion 12. It isnoted that each tooth is formed accurately, and all of the teeth areuniformly twisted since none of the teeth is attached to the strip otherthan by frictional engagement of the periphery of the blanked body 76with the surrounding sheet material. Furthermore, the sharp-cornerededges 18 originally formed by the blanking punch and die are preservedsince the cooperating faces of the forming punch and die will twist thesheet material lying between radially projecting portions '78, asillustrated at 88 in FIGURE 11, as well as the portions 78 themselvesand will not tend to wipe the sharp-cornered edges against surroundingsheet material which might otherwise remain stationary during twisting.The die set is again opened and the strip is indexed to place location;L below the push rod 58 and the upper platten is reciprocated therebybringing the push rod into contact with the blanked body 76 which nowhas twisted teeth and is actually a completed lock washer so as to pushthe blanked body with the twisted teeth out of engagement with the stripwhereupon a finished toothed lock washer 10 is delivered through chute72.

In the manufacture of toothed lock washers of generally standard sizesfrom commonly available sheet materials, the relative proportions of thewasher and the material thickness are such that the operation of theblanking punch and blanking dies as described above will actually cut ablank completely through the strip so that the blanked body 76 issevered from the surrounding sheet material completely around the entireperiphery of the body 76. The pushing of the body back into the strip bythe operation of inserts 54 and 64 then serves to increase thefrictional forces which retain the blanked body within the strip fortransport throughout the remaining steps of the lock washer formingprocedure. For example, in the fabrication of a typical toothed lockWasher of spring steel for engagement with a threaded bolt having anominal diameter of a quarter of an inch, the sheet material would havea thickness of about 0.025 inch and the blanking punch would displacethe blanked body about two-thirds of the way out of the sheet, or about0.017 inch downwardly, as seen in FIG- URE 8, and the blanked body wouldbe completely severed from the surrounding sheet around the entireperiphery thereof, but would be held within the sheet by frictionalengagement with suflicient force to be transported and placed betweenthe anvils at the next station in the apparatus where the blanked bodyis pushed back into the sheet so as to establish an even greaterfrictional force and assure that it is retained in the sheet throughoutthe subsequent twisting operation of the forming punch and die. However,it is conceivable that under certain conditions the dimensions andmaterials may be such that the partial blanking performed by theblanking punch and die would form the blanked body completely around theentire outer periphery thereof but would not necessarily sever theblanked body completely from the surrounding sheet material around theentire periphery thereof. In such instances, the severence will becompleted by pushing the blanked body back into the sheet at the nextsubsequent station so that a completely severed blanked body ispresented to the forming punch and die.

It is common knowledge that the economical operation of presses of thetype which would accept and operate die set 3i! is fostered by providingmore than one series of tools with all series operating simultaneouslyso that for each operating stroke of the press, a plurality of lockwashers is being fabricated. It is also well known that the severalseries of tools can be arranged so that a saving is realized in sheetmaterial stock by seeing that the blanked bodies are placed close enoughtogether in the strip to make use of that material which mightordinarily become waste. However, in fabricating devices such as lockwashers 10, it has been found that the simultaneous operation of severalseries of tools will place such a great deal of stress upon the strip ofmaterial as it passes through the apparatus that distortion will occurin the form of unwanted stretching of the sheet both laterally andlongitudinally. Since the amount of such stretching is relatively small,the lateral stretching can be compensated for rather easily or evencompletely disregarded. However, the longitudinal stretching becomescritical since each small amount of elongation in the strip along theline of the travel of the strip imparted by the operation of aparticular tool is cumulative to those amounts already imparted as thestrip travels through the apparatus and the overall elongation canbecome so great as to cause problems in registering a particular blankwith the several tool stations through which it must pass. The methodand apparatus of the instant invention overcomes the problem ofelongation of the strip while still providing several simultaneouslyoperating series of tools in a manner which will now be explained,

Returning now to FIGURES 3 and 4, the additional two series of tools inthe upper and lower tool holders have been identified with referencecharacters corresponding to the already described first series, thesecond series being comprised of a piercing punch 150, a blanking punch152, an anvil 154, a forming punch 156, and a push rod 158 each fixed inthe upper tool carrier 40 and lying along line B which is aligned with alongitudinal line BB in strip 20, tools 150, 152, 154, and 156 eachhaving complementary tools in the form of a die 16!) for cooperatingwith piercing punch 150, a blanking die 162 including a concentric,resiliently supported stop member 163 for cooperating with blankingpunch 152, an anvil 164 complementary to anvil 154 and a forming die 166complementary to forming punch 156, all carried in lower tool carrier 46which also has third and fourth chutes 170 and 172 passing therethrough,while the third series of tools is comprised of like tools 250, 252,254, 256, and 258 in the upper tool carrier and lying along line C whichis aligned with a longitudinal line CC in strip 20, the above tools ofseries C having complementary tools 260, 262, 263, 264 and 266 in thelower tool carrier with fifth and sixth chutes 270 and 272 passingtherethrough. Thus, the first series will be referred to as the A serieswhile the second and third series will be referred to as the B and Cseries, respectively.

Strip 20 enters the apparatus as a solid, elongated sheet and, asdescribed above, the strip is advanced from left to right as viewed inthe figures. By following any one given longitudinal location in thestrip, such as that denoted by lateral dashed line L as the stripprogresses through the apparatus, it can be seen that the sequence ofoperations set forth in the method will first be performedsimultaneously along the outermost lines AA and BB by the tools ofseries A and B which are longitudinally spaced along outtermost lines Aand B in the apparatus. Thus, the strip will first be piercedsimultaneously along both lines A and B at the station marked pierce(see FIGURE 3), then partially blanked out of the sheet at the stationmarked punch. Then the blank is pushed back into the sheet at thestation marked push-back, and subsequently portions of the blank aretwisted at the station marked twist to complete the lock washer 10.Since the lock washer 10 is still retained in the strip after completionat the twisting station, it is carried to the removal station where thecompleted washer is pushed out of the strip by the push rod 58. Lines AAand BB are laterally spaced apart to provide enough materialtherebetween for the simultaneous fabrication of a third lock washer 10along inner line CC by the operation of the tools of series C. However,the series C tools are staggered longitudinally downstream of the seriesA and B tools so that they do not begin to operate upon the strip 20until after the completion of the lock washers in the outermost lines AAand BB. Thus, piercing punch 250 is located beyond forming punches 56and 156 in the direction of travel of strip 20 and the solid materialwhich exists between the outermost lines during fabrication of the lockwashers therein serves as an unbroken web to reinforce the strip andpreclude unwanted elongation or longitudinal strain in the strip whichmight otherwise result from the stresses arising out of the simultaneousoperation of the tools of series A and B. Since only one series of toolsoperates along the inner central line CC, the stress placed upon thestrip is insignificant from the standpoint of strain produced,especially in View of the reinforcing structure povided by the remainderof the strip. Waste of stock is minimized by the nesting of the lockwashers formed along the inner line between the perforations remainingin the sheet after the lock washers already formed along the outer lineshave been removed. It will be apparent that the relative location of thethree illustrated tool series could be repeated to provide any desiredodd number of laterally spaced longitudinal .lines along which lookwashers will be fabricated by a series of tools along those lines andthe station sequence would be the same; that is, the outermost lineswould be operated upon to complete lock Washers therein prior to thecommencement of operations upon the innermost lines in such sequencethat a reinforcing web is always provided between lines which are beingoperated upon simultaneously at any given longitudinal location in thestrip of sheet material. Finally, as the strip 20 leaves the apparatus,the strip is cut by blades 59 and 69 at the station marked cut-off intorelatively short pieces of scrap for ready disposal.

It is to be understood that the above detailed description of anembodiment of the invention is presented by Way of example only. Variousdetails of steps, design and construction may be modified withoutdeparting from the true spirit and scope of the invention as set forthin the appended claims.

What is claimed is:

1. A method of making toothed lock washers from sheet material, eachwasher having a generally annular body portion with teeth projectingradially from said body portion and being spaced circumferentially fromone another and twisted relative thereto to establish locking edgesdisplaced axially from at least one surface of the body portion, saidmethod comprising the steps of:

at least partially blanking a body with radially projecting portionsspaced circumferentially from one another and corresponding to saidteeth in the sheet such that the blanked body is completely formedaround the entire outer periphery thereof and is not displacedcompletely out of said sheet;

pushing said blanked body back into said sheet such that the body isretained in the sheet solely by frictional engagement of the peripheryof the body with the sheet material;

twisting said radially proiectin g portions of the blanked body and thesheet material lying between the radially projecting portions while theblanked body is retained in the sheet by said frictional engagement toestablish said locking edges; and

removing said body with the twisted teeth from the sheet.

2. A method of making toothed lock washers from sheet material, eachwasher having a generally annular body portion with teeth projectingradially from said body portion and being spaced circumferentially fro-mone another and twisted relative thereto to establish locking edgesdisplaced axially from at least one surface of the body portion, saidmethod comprising the steps of:

forming a blank having a body with radially projecting portions spacedcircum'ferentially from one another and corresponding to said teeth bysevering said blank from the sheet of material around the entire outerperiphery of said blank;

retaining said blank within the sheet by frictional engagement of atleast a portion of the severed periphcry of the blank with the sheetmaterial;

twisting said radially projecting portions of the blanked body and thesheet material lying between the radially projecting portions while theblank is retained in the sheet by said frictional engagement toestablish said locking edges; and

removing said body with the twisted teeth from the sheet.

3. The method of claim 2 wherein the sheet material is in the form of anelongated planar continuous longi tudinal strip of material and saidforming step includes punching said blank and displacing the punchedblank out of the plane of the strip until the blank is severed from thesheet around the entire outer periphery of the blank; and

said retaining step includes pushing said severed blank back into thestrip for establishing sufiicient frictional engagement of the severedperiphery with the strip to retain the blank for the twisting step.

4. The method of claim 3 wherein the sheet material is in the form of anelongated planar continuous longigitudinal strip of material, the lockwasher includes an annular body portion with a central aperture and theteeth of the lock washer project radially outwardly from the outerperiphery of the body, and

said forming step includes piercing said strip to establish said centralaperture and punching said blank and displacing the punched blank out ofthe plane of the strip until the blank is severed from the strip aroundthe entire outer periphery of the blank including the outwardlyprojecting portions, but not removed from engagement with the strip; and

said retaining step includes pushing said severed blank back into thestrip for establishing sutficient frictional engagement of the severedperiphery with the strip to retain the blank for the twisting step;

said twisting step serving to complete the lock washer.

5. The method of claim 4 wherein the strip is ad vanced longitudinallyand the steps are performed sequentially at spaced positions along alongitudinal line in the strip to fabricate lock washers in said line,said strip having an odd number of such lines spaced laterally acrossthe strip with corresponding steps in each line being performedsimultaneously, each step performed along the outermost of said lines atany given longitudinal location along the strip being completed prior tothe commencement of a corresponding step performed along the innermostof said lines at the same given location in the strip such that the lockwashers are completed in the outermost of said lines prior to thecommencement of the fabrication of the lock washers in the innermost ofsaid lines whereby the outermost of said lines are connected by anunbroken, relatively strong web of strip material at least untilcompletion of the lock washers in the outermost of said lines at saidgiven location in the strip.

6. The method of claim 5 wherein the steps are sequentially performedalong each of at least three longitudinal lines with like steps beingperformed simultaneously along the outer two of said three lines at anygiven longitudinal location along the strip and each such steps beingcompleted prior to the commencement of a corresponding step performedalong the inner of the three lines at said given location in the stripsuch that the lock washers are completed in the outer two lines prior tothe commencement of the fabrication of the lock washers in the innerthird line whereby the outer two lines are connected by an unbroken,relatively strong web of material at least until completion of the lockwashers in the outer two lines at said given location in the strip.

7. The method of claim 6 wherein the twisting step is completed alongeach of the outer two of said three lines at said given location in thestrip prior to the commencement of the piercing step performed along theinner third line at said given location in the strip.

8. Apparatus for making toothed lock washers from sheet material, eachwasher having a generally annular body portion with teeth projectingradially from said body portion and being spaced circumferentially fromone another and twisted relative thereto to establish locking edgesdisplaced axially from at least one surface of the body, said apparatuscomprising:

opposed plattens arranged for relative reciprocating motion;

means associated with said plattens for at least partially blanking abody with radially projecting portions spaced circumferentially from Oneanother and corresponding to said teeth in the sheet such that theblanked body is completely formed around the entire outer peripherythereof and is not displaced completely out of said sheet;

mean associated with said plattens for pushing said blanked body backinto said sheet such that the body is retained in the sheet solely byfrictional engagement of the periphery of the body with the sheetmaterial;

means associated with said plattens for twisting said radiallyprojecting portions of the blanked body and the sheet material lyingbetween the radially projecting portions while the blanked body isretained in the sheet by said frictional engagement to estab lish saidlocking edges; and

means associated with said plattens for removing said body with thetwisted teeth from the sheet.

9. Apparatus for making toothed lock washers from sheet material, eachwasher having a generally annular body portion with teeth projectingradially from said body portion and being spaced circumferentially fromone another and twisted relative thereto to establish locking edgesdisplaced axially from at least one surface of the body portion, saidapparatus comprising:

opposed plattens arranged for elative reciprocating motion: meansassociated with said plattens for forming a blank having a body withradially projecting portions spaced circumferentially from one anotherand corresponding to said teeth by severing said blank from the sheet ofmaterial around the entire outer periphery of said blank; meansassociated with said plattens for locating sail blank relative to saidsheet for retention of said blank within the sheet by frictionalengagement of at least a portion of the severed periphery of the blankwith the sheet material; means associated with said plattens fortwisting said radially projecting portions of the blanked body and thesheet material lying between the radially projecting portions while theblank is retained in the sheet by said frictional engagement toestablish said locking edges; and means associated with said plattensfor removing said body with the twisted teeth from the sheet. 10. Theapparatus of claim 9 wherein the sheet material is in the form of anelongated planar continuous longitudinal strip of material and saidforming means includes a blanking punch for punching said blank out ofthe plane of the strip until the blank is severed from the sheet aroundthe entire outer periphery of the blank; and

said means for locating said blank relative to said sheet for retentionof said blank within the sheet include anvil means for pushing saidsevered blank back into said strip until said blank is suflicientlyfrictionally engaged with the strip along the severed periphery toretain the blank within the strip for presentation to said twistingmeans.

11. The apparatus of claim 10 wherein the sheet material is in the formof an elongated planar continuous longitudinal strip of material, thelock washer includes an annualr body portion with a central aperture andthe teeth of the lock washer project radially outwardly from the outerperiphery of the body, and

said forming means include a piercing punch for piercing said strip toestablish said central aperture and a blanking punch for punching saidblank and displacing the punched blank out of the plane of the stripuntil the blank is severed from the strip around the entire outerperiphery of the blank including the outwardly projecting portions, butnot removed from engagement with the strip; and

said means for locating said blank relative to said sheet for retentionof said blank include anvil means for pushing said several blank backinto said strip until said blank is sufliciently frictionally engagedwith the strip along the severed periphery to retain the blank withinthe strip for presentation to said twisting means wherein the lockwasher is completed.

12. The apparatus of claim 11 wherein the strip is advancedlongitudinally through the apparatus and the individual means arelocated in spaced positions along a longitudinal line corresponding witha longitudinal line in the strip to fabricate lock washers in said linein the strip, said apparatus having an odd number of such lines ofspaced means spaced laterally to correspond with an odd number of linesspaced laterally across the strip with corresponding means in each linebeing capable of simultaneous operation, the spaced means along theinnermost of said lines of spaced means being staggered longitudinallyrelative to corresponding spaced means in the outermost of said linessuch that the operation of any means upon the strip along the outermostof said lines at any given longitudinal location in the strip iscompleted prior to the commencement of the operation of correspondingmeans along the innermost of said lines at the same given location inthe strip and the lock washers are completed in the outermost of thelines in the strip prior to the commencement of the fabrication of thelock washers in the innermost of the lines in the strip whereby theoutermost of said lines in the strip are connected by an unbroken,relatively strong web of material until completion of the lock washersin the outermost of said lines at said given longitudinal location inthe strip.

13. The apparatus of claim 12 including means for simultaneouslyoperating all of said longitudinally spaced means, said longitudinallyspaced means being located at spaced positions along one of at leastthree longitudinal lines corresponding with at least three longitudinallines in said strip, said operating means operating said spaced meansalong the outer two of said three lines simultaneously at any givenlongitudinal location along the strip such that the operation of any onemeans in each of said outer two lines is completed prior to thecommencement of the operation of corresponding means in the inner ofsaid three lines at said given location in the strip such that the lockwashers are completed in the outer two lines in the strip prior to thecommencement of the fabrication of the lock washers in the inner thirdline in the strip whereby the outer lines in the strip are connected byan unbroken relatively strong web of material until COmpletion of thelock washers in the outer two lines at said given location in the strip.

14. The apparatus of claim 13 wherein the piercing punch of the inner ofthe three lines of spaced means is located longitudinally beyond thetwisting means of each of the outer two of said lines of spaced means inthe direction of travel of the strip.

References Cited UNITED STATES PATENTS 444,917 1/1891 Mason l0861,659,161 2/1928 Richer 10-86 1,785,281 12/1930 Olson 10-73 1,915,6126/1933 Olson 1073 2,234,194 3/ 1941 Poupitch 10-86 2,352,118 6/ 1944Poupitch 10-86 2,829,488 4/1958 Valli 59-65 RICHARD J. HERBST, PrimaryExaminer. E. M. COMES, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 ,381,514 May 7 Fred Schmidt et a1.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as' shown below:

Column 1, line 27, "fabricated" should read fabricating Column 2, line68 "platen" should read platten Column 5, line 71, "outtermost" shouldread outermost Column 8 line 34 "mean" should read means Column 9, line30, "several" should read severed v Signed and sealed this 14th day ofOctober 1969.

(SEAL) Attest:

M. Fletcher, Jr. WILLIAM E. SCHUYLER,- JR.

Aitesting Officer Commissioner of Patents

